I think the yogurt cheese idea is a great one. I'd try that before tofu, because it will be more like what your dc is used to. And so far as the sundried tomatoes go, yes, I would switch to the dry ones, but I'd rehydrate them with boiling water (pour the boiling water over the tomatoes, don't boil them). I think the liquid needs to be hot for it work. But maybe it would just take longer if you put them in the yogurt. You could always try it, and if it didn't work, you could pour hot water over them. Anyway, I think you're on the right track.
Christie
Christie